A second ADSC Quantum-4 CCD detector was delivered to SSRL in the spring of 1998. This detector was mounted on BL1-5 in place of the first Quantum-4 detector, that was received in 1997. After being successfully tested, this detector was used for data collection on this beam line for the remainder of 1998. For acceptance testing, data sets from flash-cooled P6 crystals of myoglobin were collected and the data, when reduced, met the rigorous acceptance specifications of the purchase documents. Use of the new detector on BL1-5 will continue for the foreseeable future. Users have been very positive about its use on this line.